The effects of titanium mesh cage size on the biomechanical responses of cervical spine after anterior cervical corpectomy and fusion: A finite element study

Due to the lack of sufficient studies focusing on titanium mesh cage size, there exists a puzzle among surgeons about how to determine the optimal size of cage to provide surgical segments an adequate distraction.The biomechanical responses of cervical spine after the implantation of cages with different heights and trimmed angles were analyzed using the finite element method. Twenty Anterior Cervical Corpectomy and Fusion models, of which the surgical segment was C5, were developed corresponding to the combinations of 4-different-heights and 5-different-trimmed angle cages. Biomechanical parameters were calculated under simulated physiological load of cervical spine. A rating scale was designed to assess the biomechanical performances of titanium mesh cages with different heights and trimmed angles comprehensively, assisting to select the most appropriate combination of cage height and trimmed angle.It was indicated that in the single-level Anterior Cervical Corpectomy and Fusion at C5 segment, a cage with a height fitting with the space between C4 and C6 as well as a trimmed angle 2° lower than the sagittal angle of C4 inferior endplate would provide adequate biomechanical environment for cervical spine to resist cage subsidence and reduce the impact to adjacent segments.The biomechanical responses of cervical spine are affected significantly by the height and trimmed angles of titanium mesh cage. The results of this study would provide quantitative guidance for surgeons to determine the optimal height and trimmed angle of titanium mesh cage for a specific patient in order to achieve favorable clinical outcomes.